Chemical combination - Jamb Chemistry Past Questions and Answers

Question 116:

• JAMB 2008

2Na_(s) + 2H₂O_(l) → 2NaOH_(aq) + H_2(g)
From the equation above, calculate the mass of sodium hydroxide produced by 2.3g of sodium.
[H = 1, O = 16, Na = 23]

A. 0.40g
B. 0.80g
C. 4.00g
D. 8.00g

Question 117:

• JAMB 2008

16.8 g of sodium hydrogen trioxocarbonate (IV) is completely decomposed by heat. Calculate the volume of carbon(IV) oxide given off s.t.p
[Na 23, C = 12, O = 16, H = 1, Molar volume of a gas at s.t.p = 22.4 dm³]

A. 22.40 dm³
B. 11.20 dm³
C. 2.24 dm³
D. 1.12 dm³

Question 118:

• JAMB 2008

300 cm³ of gas has a pressure of 800 mmHg. If the pressure is reduced to 650 mmHg, find its volume

A. 243.75 cm³
B. 369.23 cm³
C. 738.46 cm³
D. 1733.36 cm³

Question 119:

• JAMB 2008

0.05 mol dm^-3 HCl is neutralized by 25 cm³ NaOH. If the volume of acid used is 32.00cm³, what is the concentration of the base

A. 0.016 mol dm^-3
B. 0.032 mol dm^-3
C. 0.039 mol dm^-3
D. 0.064 mol dm^-3

Question 120:

• JAMB 2009

0.0075 mole of calcium trioxocarbonate (IV) is added to 0.015 mole of a solution of hydrochloric acid. The volume of gas evolved at s.t.p is
[Molar volume of a gas at s.t.p = 22.4 dm³]

A. 224cm³
B. 168cm³
C. 112cm³
D. 100cm³